75 separator rebuild

Wow
Like most, I'm typically not an I/O guy, but I have a weakness for I/O thru-hulls. With that look and sound somehow this one's like evil incarnate, bravo, well done!

Well I had the fastest correct craft for a while, get a GPS on that thing to capture the real speed.

When you switch to the 26 the same thing will happen but at lower RPM. Chinewalking hits me at 70, and I have TONS of RPM left in the motor. I also need to figure out how to drive it. I was hitting 70 mph with a 26p at 6800 RPM and the chine walking would start. With the 24p I would get the same thing at 70mph, but RPM's were just above 7000 (who has time to look at the tach or GPS anyway...).

Get some video too, and screen shots of your max GPS speed.

Chevy350 wrote: Chine walking?

Side to side movement typically with a yaw.

Geez Jeff, that is wild!

Justin;

When you are flying these boats (because essentially that is what you are trying to do, get as much boat out of the water as possible), they end up tettering on a relatively unstable portion of the boat because so little of the hull is in the water. In the case of the Bass Nautique (an most vee hulls) their is a 10 inch wide pad (flat spot) on the bottom of the hull, here is a picture of the Bass Nautique Pad:


I don't think the Seperator even has a pad that is this wide if it has one at all. The object is to trim the boat so as little the boat is in the water as possible. Here is a picture that illustrates that, as you can see, only about 12 to 18 of the aft end of the hull is in the water:


As you go faster, this becomes very unstable, especially with the Seperator as it continues to rise out of the water. Chine walking begins when you "fall off the pad" or the boat leans to one side. When it does this it eventually finds the water and for lack of a better term "bounces" (it's actually more of a the hull hits the water planes off) and starts leaning the other way. It now has force that it comes back up on the pad and then immediately goes over the pad to the other side, "bouncing" again back in the first direction. If left un-corrected this will continue until the boat goes so far over that it hits one of the chines, catches and "hooks" or makes a very sharp uncontrollable turn, usually ejecting anyone in the boat. VERY dangerous condition.

If you are quick enough and experienced, you can counter-steer when it starts to fall off the pad, boat falls to the right you steer to the left (to pick up the right side of the boat), this is how you "drive through it. Otherwise you have to ROLL off the throttle smoothly (remember with an outdrive,(power gives you control -there is no rudder, so you can't chop the power) and trim down the drive.

Joe and Tim's boats also do this, Tim's more then Joe's as the Barefoot also has a deep-vee, instead of the flatbottomed ski nautique. Any boat will chine walk (well except for a tunnel hull) when you start to operate it where it gets unstable.

Beyond chine walking is running on the lower unit cavitation plate. Been there once and you have zero control.

JPASS wrote: Good God man she sounds awesome.